Short answer: yes, you need some kind of external device plugged in — a Fire TV Stick, a Jio set-top box, a console, a Chromecast, anything with an HDMI output. Here's why, and what happens if you don't have one.
How an HDMI sync backlight actually works
An HDMI sync box reads the video signal passing through it and works out what colours are on screen, then sends those colours to the LED strip behind your TV. The important part is passing through it.
The chain looks like this:
Fire TV Stick (or console, or set-top box) → HDMI sync box → TV
Your source device plugs into the sync box. The sync box plugs into the TV. Everything you play travels through the box on its way to the screen, so the box can read it and match the lighting in real time.
Why it can't sync with your TV's built-in apps
If you open Netflix from your TV's own home screen, that video is generated inside the TV. It never travels through an HDMI cable, so it never passes through the sync box. The box has nothing to read, and the lights won't follow the picture.
This isn't a fault or a limitation of one brand — it's true of every HDMI sync backlight on the market. It's simply how the technology works.
What syncs and what doesn't
Syncs perfectly: Netflix, Prime Video, Hotstar, YouTube and everything else — as long as you play them from a Fire TV Stick, Chromecast, Apple TV, set-top box or console connected to the sync box. Games on PS5 and Xbox sync too, including at 4K 120Hz on HDMI 2.1 kits.
Won't sync: anything opened from the TV's own built-in app menu, and anything played directly off a USB drive plugged into the TV.
So Netflix does sync. It just has to come through the box.
Which streaming device should you use?
Any HDMI source works. Most customers in India already have one of these:
- Fire TV Stick — cheapest and most common. The 4K version is worth it if your TV is 4K.
- Jio, Tata Play or Airtel set-top box — already in most living rooms, and it works fine.
- Chromecast with Google TV — good if you're in the Google ecosystem.
- PS5 or Xbox Series X — doubles as your streaming device and your console.
If you already own one of these, you don't need to buy anything extra.
What if I only use my TV's built-in apps?
Then buy a Fire TV Stick. It's a small outlay, it plugs into the sync box, and every app you currently use from the TV menu is available on it. Most people find the interface faster than their TV's built-in one anyway.
What if I have several devices?
Count your sources before you choose a kit. If you run a console, a set-top box and a streaming stick, you want enough HDMI inputs on the sync box so you're not unplugging cables. The AmbiMotion 2.1 Pro has three HDMI 2.1 ports for exactly this.
For a single source, a standard kit is enough.
Setting it up
- Plug your streaming device or console into an input on the sync box.
- Run one HDMI cable from the sync box output to your TV.
- Mount the LED strip around the back edge of the TV panel.
- Power the sync box and pair it in the app.
- Switch your TV to the HDMI input the sync box is on — not the TV's home screen.
That last step catches people out. If your TV is showing its own menu, the sync box isn't in the picture.
Do PC monitors need a sync box too?
No. Our monitor range works differently — Ambit 2 and Gleam GBar2 connect to your PC over USB and read the screen through desktop software. No HDMI box, no extra hardware.
Browse the full range of TV backlight kits, all with the sync box included.